SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df5503966f3cc037694e3f0c637af87b1c30a72e34bcb512ed95d15c8e32064d' 
  AND token = 'S2CtNb1q1rXS4NSG1n8LhB1ysS1Gol7xSG907lINEYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}